Method and apparatus for manufacturing mineral wool



METHOD AND APPARATUS FOR MANUFACTURING MINERAL WOOL Filed Oct. 10, 1941 ATTORNEY Patented Sept. 26, 1944 METHOD ANDI APPARATUS FOR MANU- FACTUBING MINERAL WOOL Joseph H. Zettel, Plaineld,

N. J., assignor to n Johns-Manville Corporation, New York, N. Y., a corporation of New York Application October 10, 1941, Serial No. 414,484 1o claim. (cl. 154-27) The present invention relates to improvements in the manufacture of felted mineral wool products and more particularly to improvements in methods and apparatus for collecting and felting mineral wool fibres. It will be understood that the term mineral wool is employed herein in a generic sense to denote fibres, or products formed from bres, made from rock, slag, glass, and other such raw materials and mixtures thereof.'

conventionally, mineral wool is manufactured by disintegrating a molten stream of raw material into a multiplicity of fibres by means of a steam blast or the like. A binder is applied adjacent to the blast by dripping, spraying, or otherwise injecting the binder into the suspen-v sion of fibresl in the gaseous stream created by the blast. The suspension of bres and intermingled binder enter a blow chamber and are collected on the floor thereof, on a suitable conveyor, in interielted relationship. Where relatively large amounts of a combustible binder are employed, such as asphalt or other bitumens, waxes, or the like, it has heretofore been necessary to include with the binder a suitable fireprooflng ingredient, such as a chlorinated, aromatic or cyclic hydrocarbon, for example, the material sold under` the name Halowax. As willl be understood, when, say, fifteen per cent or more binder .,(determined on the weight of the felt) is employed without a reprooiing cannot occur.

ized forminto the suspension of libres and bind- The moisture settles with the. fibres vand uniformly permeates the felt, cooling and wetting it to such an extent that destructive fires At the same time a sufficient amount ofthe moisture is evaporated into the air entering, theblow chamber with the fibres to create high humidity conditions in the blow chamber.

In addition to the foregoing, it has been determined that the water permeating the felt imrproves the quality thereof in that the water aids in forming loosely felted material more evenly deposited over the' blow chamber conveyor. Also the water reduces binder ignition loss in the hot blast.

My invention will be fully understood and further objects and advantages thereof will become apparent when reference is made to the morel detailed description thereof which is to follow and to the accompanying drawing, in which the single figure is a diagrammatic elevational View, with parts broken away for the pur'- pose of illustration of a fibre-forming and receiving apparatus incorporating the instant invention.

Referring now to the drawing, there is shownV a melting furnace I0, which may be a cupola agc'ent, ignition of the binder is caused by slugs f or cchips of hot slag which inevitably fall into the blow chamber. The localized fires thus started at times spread into large fires destroying a large portion of the felt as a. commercial product and sometimes causing the rapid burning of loose dry material hanging on the side walls of the blow chamber with a minor explosive eect. The chlorinated hydrocarbons previously employed as flreprooiing agents have unduly increased the cost of manufacture and, furthermore, have been diicult to handle and have caused trouble in the binder supply equipment as well as creating dangerous fume conditions.

The principal object of the instant invention is the provision of a method and apparatus which will prevent fires in the blow chamber and at the same time will not add in any substantial degree to the cost of the operation or in any way impair the quality of the product formed.

Another object is the provision of a method and apparatus to condition the blow chamber and the felt formed therein so that combustion of the binder is prevented.

A still further object of the invention is the provision of such a method and apparatus as will result in an improved product.

Briey stated, my invention resides in the addition lof a given quantity of moisture in atomor tank furnace of any conventional design, a cupola being selected for purposes of illustration. The molten slag, rock, or other mineral-woolforming material flows from the cupola and falls in a stream into the path of a jet l2 of high pressure steam or the like issuing from a nozzle I4. A suitable binder is projected into the suspension of newly formed fibres, for example, as-

by spraying the binder into the suspension through nozzle I6. lIt will be understood that the' instant invention is not limited to the use of any particular type of binder, but/is of particular importance where relatively large proportions, say fteen per cent or more by weight of the product, of combustible binders are used, such as aslphalt, asphalt fluxes, gilsonite, resins, waxes, and similar thermoplastic materials. The fibres and binder carried in the gaseous suspension enter a blow chamber indicated generally at I6 and settle therein onto the floor, preferably comprising a movable conveyor i8 which carries the felt thus formed from the blow chamber to subsequent operations. Y

In accordance with the instant invention, one or more water sprays 20 are provided, preferably one below and one above the blast, the sprays being of a character to inject water in atomized form intothe suspension of fibres. Preferably the sprays are directed at substantially a 45"angle to the main direction of movement of the suspension. Valves 22 are provided whereby the quantity of water entering the blow chamber can be controlled to conform with varying conditions.

In the operation of the apparatus and method, a suflicient amount of moisture is sprayed into the suspension of bres and binder, to create a humid atmosphere in the blow chamber which will inhibit blow -chamber explosions, and to cause a moisture content in the .felt suiiicient to" prevent `vthe occurrence of destructive fires.

It has been determined that, where a combustible binder content of approximately fifteen per cent by weight of the felt is employed, the amount of moisture in the felt should constitute from one to four per cent of the weight of the felt, It will be understood, however, that variations in they type of binder, the quantity employed and the humidity conditions` prevailing may cause varia-` .tions in the amount of moisture to be added.

A further feature of this invention resides in the inclusion in the water spray of a relatively small percentage, say of the order of two per cent based upon the weight of the felt, of a drying ad- 'hesive such as a ligneous adhesive material, for

example, calcium ligno-sulphonate. It has been determined that, although no subsequent heat treatment is employed, the inclusion of the small proportion of an adhesive of thistype serves to increase the strength of the .product beyond what would normally be expected, considering the amount of the material used. The adhesive may be mixed into the water spray in any suitable manner.

Having thus described my invention in rather full detail, it will be understood that these details need not be strictly adhered to, but'that various layer with water in minor quantities substantially uniformly distributed therein.

2. The method of manufacturing felted mineralwool products comprising disintegrating a stream of molten material into a multiplicity of fibres, forming a gaseous suspension of said fibres and a' iinely divided combustible binding material. spraying water in atomized form into said suspension, and collecting said fibresV in a layer with the water in minor quantities substantially uniformly distributed therein.

3. The method of manufacturing felted mineral wool .products comprising projecting a steam blast against a stream of molten material to convert the same into a multiplicity of fibres, forming a gaseous suspension of said libres and a nnely divided combustible bindingV material, spraying atomized moisture into said suspension adjacent to the place of formation of said suspension, and collecting said fibres in a layer.

4. 'Ihe method of manufacturing felted mineral wool products comprising projecting a steam blast against a stream of molten material to convert the same into a multiplicity of fibres, formingl a gaseous suspension oi.' said fibres and a finely divided combustible binding material present in proportion of the order of by weight of the iiynished product, spraying atomized moisture into said suspension, and collecting said fibres in a layer, the amount of moisture project ed into said suspension by said spray being sumcient to provide a moisture content in lsaid'layer of the order of l to 4% by weight of the layer.

5. The method of manufacturing felted mineral wool products comprising disintegrating a stream of molten material into a multiplicity of iibres, forming a gaseous suspension of said libres and of a finely dividedcombustible binding material present in amounts to provide a binder content of at least 15% by weight of the prod- .uct, spraying water including a drying adhesive into said suspension in suillcient quantities to provide a moisture content insaid product of the order of 1-4% by weight o f the product, and collecting said fibres in a layer. I

6. v'I'he method of manufacturing felted mineral wool products comprising disintesrating a stream of molten Vmaterial into a multiplicity of bres, forming a gaseous suspension of said libres and a finely divided combustible binding material present in amounts to provide a binder con,- tentv of at least 15% by weight of the product, spraying water including ligneous adhesive material into said suspension in suillcient quantities to provide a moisture content in said product of the order of 14% by weight ofthe product, and collecting said nbres in a layer.

'1. The method of manufacturing felted mineral wool products comprising disintegrating a stream of molten material into a multiplicityof fibres, forming a gaseous. suspension of said fibres anda nely divided combustible binding material present in amolmts to .provide a binder content of at least 15% by weight of the product, spraying water including calcium ligno-sulphonate into said suspensiomin suiiicient quantities to provide a moisture content in said Aproduct of the order of 1-4% by weight of the product, and collecting said fibres in a layer.

8. The method of manufacturing felted mineral wool products comprising disintegrating fa stream of molten material into a multiplicity of fibres, forming a gaseous suspension of said libres and a ilnely divided combustible binding material present invamounts to provide a binder content of at least 15% by weight of the product, spraying water including calcium lignosulpho nate into said suspension in proportions of the order of 2% byweight of the product, and co1- lecting said fibres in 1a layer.

9. An apparatus comprising means for disintegrating a stream of molten material into a multiplicity of fibres carried in gaseous suspension, means for injecting a finely divided binder into said suspension, means for spraying atomized water into said suspension adjacent said disintegrating means and at an angle to the direction of movement of said suspension, and means for collecting said suspension in the form of a felt.

10. An apparatus comprising a steam blast for disintegrating a stream of molten material into a multiplicity oi' fibres carried in gaseous suspension, means for injecting a. finely divided binder into said suspension, atomizing spray heads adiacent said blast and above and below the same for projecting water into said suspension, and means for collecting said suspension in the form of a l felt.

JOSEPH H.. ZEI'IEL. 

